Quote:
Originally Posted by Frank Lee
I'd have to run ridiculously high psi to achieve a square patch, or achieve some radical weight loss on the car, or both. It just may be that the stock size is already the optimal one.
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Thanks for the Coker idea. I'll take a look.
Edit: (Original thread updated)
1.) Could someone verify how you calculate the psi needed for a square contact patch?
I'm assuming it's just:
vehicle weight / (4 * area of square contact patch)
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Hypothetically, a CRX HF that weights 1700lbs running a tire psi of 70 (reasonable for a "temporary" tire) would only need tires 2.46" wide (62mm).
My Thunderbird, which weighs ~3569lb, running 55psi would only need a tire 4.03" wide (102mm).
Tire width would need to increase with load (driver, gas, oil, etc.) and traction would be severely reduced, but does this sound reasonable? Those tires would be extremely skinny. 
2.) If skinny enough tires don't exist, what is better: a square contact patch or max psi?
A higher psi causes more rubber to deflect than an ideal tire, but it is still an equal amount to the square contact patch of a lower psi. I would say higher psi simply because the amount of rubber being deflected will always equal, but the tire will be stiffer and therefore incur less friction.
I think this is another relevation: In the absence of an ideal tire width, maximum psi offers lower rolling resistance than a square contact patch.
Assuming the conclusions being made are correct, this thread has been extremely useful to me. I'm surprised...and happy.
- LostCause